The present invention relates generally to telecommunications equipment, and more particularly to customer premise interfaces for digital subscriber line devices.
Modems for digital subscriber line (xe2x80x9cDSLxe2x80x9d) applications require a signal transform device such as a bandpass filter, low-pass or high-pass filter, or other network having a signal transform function for providing a signal coupling interface to existing customer premise equipment. Such modem devices include ADSL modems, RADSL modems, HDSL modems, and the like. xDSL is a common acronym used to describe a wide range of digital subscriber loop technologies such as ADSL, RADSL and HDSL. As is well known, ADSL is an acronym for Asymmetric Digital Subscriber Line; similarly RADSL signifies Rate Adaptive Digital Subscriber Line and HDSL signifies High Speed Digital Subscriber Line. The aforementioned signal transform device may be used for example, to allocate spectral bandwidth among standard telephone equipment, generally including low-speed devices, and high-speed digital modem equipment. Conventional signal transform devices may be installed at the customer premise demarcation point. The demarcation point is the location in the customer""s building where the telephone company lines tie into the internal lines owned, rented or leased by the customer. Signal transform devices connect in series between each telephone company line and each respective customer line. By connecting in series, the signal transform device routes the xDSL signals to a xDSL modem and allows the standard loop start telephone signals to operate to and from telephone sets, PBXs or equivalent voice-band equipment.
The series-only interconnection of conventional signal transform devices requires consumers to pay for costly installation by qualified telephone equipment service personnel. In addition, separate wiring must be installed between the signal transform device at the demarcation point and the xDSL modem. Separate wiring for the xDSL modem further adds to the installation cost and complexity when using conventional xDSL signal transform devices.
If a means is provided to enable users to install xDSL modem equipment without the need for expert installation personnel and if such means additionally enables the user to install the xDSL equipment in any location having the existing line interface jack, then added installation cost and inconvenient installation will no longer be required. The present invention overcomes the disadvantages and inefficiencies associated with existing xDSL signal transform devices by providing a device having an interface structure that enables easy, low-cost installation by the user. Instead of interconnecting in series between the telephone company central office and both the customer premise telephone equipment and the xDSL modem, the present invention may provide separate interfaces for each piece of customer equipment. Separate interfaces enable the user to install the xDSL modem wherever there is an available line interface jack.
User installation and removal for servicing of xDSL interface devices is an important consideration for user acceptance. The present invention overcomes the disadvantages and inefficiencies associated with using conventional xDSL signal transform device technologies by enabling the user to easily install the interface device at a lower cost in the user""s present system. The preferred xDSL signal transform device installation is implemented by having one version of the device for connecting standard loop start telephones sets, PBXs, other analog telephone equipment and the like while providing another version to connect the xDSL modem equipment. The present invention therefore provides a variety of user installable xDSL signal transform devices which can be installed at an existing line interface jack on the customer premises.
A minimal configuration of the xDSL Multiple-Point Interface Device (MPID), also named hereinbelow as a signal coupling interface or signal coupler, consists of one type of signal transform device for the xDSL modem, for example a high speed device, and a different type of signal transform device for the user""s telephone set, for example a low speed device. A preferred embodiment of the present invention provides interconnection to the telephone line via both an individual xDSL MPID at each telephone set and each piece of xDSL equipment. Thus each such item of equipment is individually isolated and placed in parallel with other individual telephone sets and/or xDSL equipments connected to the telephone line.
Another preferred embodiment of the present invention enables both low-band and high-band filters, networks or other signal transform devices to be selectively coupled in the telephone line responsive to conditions existing in the customer system or on the subscriber line. In one such enhanced MPID or signal coupling device a filter may be placed in the circuit upon activation of the hook switch in a connected customer device. In another such enhanced MPID or signal coupling device a filter may be alternatively connected into a circuit feeding a customer device or bypassed in response to loading changes sensed on the subscriber line.
The foregoing should be construed as merely illustrative of the pertinent features and applications of the present invention. Many other beneficial results can be obtained by applying the present invention in a different manner or modifying the embodiments described. Accordingly, a fuller understanding of the present invention may be obtained by referring to the following Drawings and Detailed Description of the preferred embodiments.